1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 25 select ARCH_HAS_CURRENT_STACK_POINTER 26 select ARCH_HAS_DEBUG_VIRTUAL 27 select ARCH_HAS_DEBUG_VM_PGTABLE 28 select ARCH_HAS_DMA_OPS if XEN 29 select ARCH_HAS_DMA_PREP_COHERENT 30 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_KCOV 36 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 37 select ARCH_HAS_KEEPINITRD 38 select ARCH_HAS_LAZY_MMU_MODE 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MEM_ENCRYPT 41 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 42 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 45 select ARCH_HAS_PREEMPT_LAZY 46 select ARCH_HAS_PTDUMP 47 select ARCH_HAS_PTE_SPECIAL 48 select ARCH_HAS_HW_PTE_YOUNG 49 select ARCH_HAS_SETUP_DMA_OPS 50 select ARCH_HAS_SET_DIRECT_MAP 51 select ARCH_HAS_SET_MEMORY 52 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 53 select ARCH_STACKWALK 54 select ARCH_HAS_STRICT_KERNEL_RWX 55 select ARCH_HAS_STRICT_MODULE_RWX 56 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 57 select ARCH_HAS_SYNC_DMA_FOR_CPU 58 select ARCH_HAS_SYSCALL_WRAPPER 59 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 60 select ARCH_HAS_ZONE_DMA_SET if EXPERT 61 select ARCH_HAVE_ELF_PROT 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_HAVE_TRACE_MMIO_ACCESS 64 select ARCH_INLINE_READ_LOCK if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 67 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 71 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 81 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 85 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 89 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 90 select ARCH_KEEP_MEMBLOCK 91 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 92 select ARCH_USE_CMPXCHG_LOCKREF 93 select ARCH_USE_GNU_PROPERTY 94 select ARCH_USE_MEMTEST 95 select ARCH_USE_QUEUED_RWLOCKS 96 select ARCH_USE_QUEUED_SPINLOCKS 97 select ARCH_USE_SYM_ANNOTATIONS 98 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 99 select ARCH_SUPPORTS_HUGETLBFS 100 select ARCH_SUPPORTS_MEMORY_FAILURE 101 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 102 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 103 select ARCH_SUPPORTS_LTO_CLANG_THIN 104 select ARCH_SUPPORTS_CFI 105 select ARCH_SUPPORTS_ATOMIC_RMW 106 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 107 select ARCH_SUPPORTS_NUMA_BALANCING 108 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 109 select ARCH_SUPPORTS_PER_VMA_LOCK 110 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 111 select ARCH_SUPPORTS_RT 112 select ARCH_SUPPORTS_SCHED_SMT 113 select ARCH_SUPPORTS_SCHED_CLUSTER 114 select ARCH_SUPPORTS_SCHED_MC 115 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 116 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 117 select ARCH_WANT_DEFAULT_BPF_JIT 118 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 119 select ARCH_WANT_FRAME_POINTERS 120 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 121 select ARCH_WANT_LD_ORPHAN_WARN 122 select ARCH_WANTS_EXECMEM_LATE 123 select ARCH_WANTS_NO_INSTR 124 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 125 select ARCH_HAS_UBSAN 126 select ARM_AMBA 127 select ARM_ARCH_TIMER 128 select ARM_GIC 129 select AUDIT_ARCH_COMPAT_GENERIC 130 select ARM_GIC_V2M if PCI 131 select ARM_GIC_V3 132 select ARM_GIC_V3_ITS if PCI 133 select ARM_GIC_V5 134 select ARM_PSCI_FW 135 select BUILDTIME_TABLE_SORT 136 select CLONE_BACKWARDS 137 select COMMON_CLK 138 select CPU_PM if (SUSPEND || CPU_IDLE) 139 select CPUMASK_OFFSTACK if NR_CPUS > 256 140 select DCACHE_WORD_ACCESS 141 select HAVE_EXTRA_IPI_TRACEPOINTS 142 select DYNAMIC_FTRACE if FUNCTION_TRACER 143 select DMA_BOUNCE_UNALIGNED_KMALLOC 144 select DMA_DIRECT_REMAP 145 select EDAC_SUPPORT 146 select FRAME_POINTER 147 select FUNCTION_ALIGNMENT_4B 148 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 149 select GENERIC_ALLOCATOR 150 select GENERIC_ARCH_TOPOLOGY 151 select GENERIC_CLOCKEVENTS_BROADCAST 152 select GENERIC_CPU_AUTOPROBE 153 select GENERIC_CPU_CACHE_MAINTENANCE 154 select GENERIC_CPU_DEVICES 155 select GENERIC_CPU_VULNERABILITIES 156 select GENERIC_EARLY_IOREMAP 157 select GENERIC_IDLE_POLL_SETUP 158 select GENERIC_IOREMAP 159 select GENERIC_IRQ_ENTRY 160 select GENERIC_IRQ_IPI 161 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 162 select GENERIC_IRQ_PROBE 163 select GENERIC_IRQ_SHOW 164 select GENERIC_IRQ_SHOW_LEVEL 165 select GENERIC_LIB_DEVMEM_IS_ALLOWED 166 select GENERIC_PCI_IOMAP 167 select GENERIC_SCHED_CLOCK 168 select GENERIC_SMP_IDLE_THREAD 169 select GENERIC_TIME_VSYSCALL 170 select GENERIC_GETTIMEOFDAY 171 select HARDIRQS_SW_RESEND 172 select HAS_IOPORT 173 select HAVE_MOVE_PMD 174 select HAVE_MOVE_PUD 175 select HAVE_PCI 176 select HAVE_ACPI_APEI if (ACPI && EFI) 177 select HAVE_ALIGNED_STRUCT_PAGE 178 select HAVE_ARCH_AUDITSYSCALL 179 select HAVE_ARCH_BITREVERSE 180 select HAVE_ARCH_COMPILER_H 181 select HAVE_ARCH_HUGE_VMALLOC 182 select HAVE_ARCH_HUGE_VMAP 183 select HAVE_ARCH_JUMP_LABEL 184 select HAVE_ARCH_JUMP_LABEL_RELATIVE 185 select HAVE_ARCH_KASAN 186 select HAVE_ARCH_KASAN_VMALLOC 187 select HAVE_ARCH_KASAN_SW_TAGS 188 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 189 # Some instrumentation may be unsound, hence EXPERT 190 select HAVE_ARCH_KCSAN if EXPERT 191 select HAVE_ARCH_KFENCE 192 select HAVE_ARCH_KGDB 193 select HAVE_ARCH_KSTACK_ERASE 194 select HAVE_ARCH_MMAP_RND_BITS 195 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 196 select HAVE_ARCH_PREL32_RELOCATIONS 197 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 198 select HAVE_ARCH_SECCOMP_FILTER 199 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 200 select HAVE_ARCH_TRACEHOOK 201 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 202 select HAVE_ARCH_VMAP_STACK 203 select HAVE_ARM_SMCCC 204 select HAVE_ASM_MODVERSIONS 205 select HAVE_EBPF_JIT 206 select HAVE_C_RECORDMCOUNT 207 select HAVE_CMPXCHG_DOUBLE 208 select HAVE_CMPXCHG_LOCAL 209 select HAVE_CONTEXT_TRACKING_USER 210 select HAVE_DEBUG_KMEMLEAK 211 select HAVE_DMA_CONTIGUOUS 212 select HAVE_DYNAMIC_FTRACE 213 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 214 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 215 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 216 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 217 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 218 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 219 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ 220 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 221 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 222 if DYNAMIC_FTRACE_WITH_ARGS 223 select HAVE_SAMPLE_FTRACE_DIRECT 224 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 225 select HAVE_BUILDTIME_MCOUNT_SORT 226 select HAVE_EFFICIENT_UNALIGNED_ACCESS 227 select HAVE_GUP_FAST 228 select HAVE_FTRACE_GRAPH_FUNC 229 select HAVE_FUNCTION_TRACER 230 select HAVE_FUNCTION_ERROR_INJECTION 231 select HAVE_FUNCTION_GRAPH_FREGS 232 select HAVE_FUNCTION_GRAPH_TRACER 233 select HAVE_GCC_PLUGINS 234 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 235 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 236 select HAVE_HW_BREAKPOINT if PERF_EVENTS 237 select HAVE_IOREMAP_PROT 238 select HAVE_IRQ_TIME_ACCOUNTING 239 select HAVE_LIVEPATCH 240 select HAVE_MOD_ARCH_SPECIFIC 241 select HAVE_NMI 242 select HAVE_PERF_EVENTS 243 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 244 select HAVE_PERF_REGS 245 select HAVE_PERF_USER_STACK_DUMP 246 select HAVE_PREEMPT_DYNAMIC_KEY 247 select HAVE_REGS_AND_STACK_ACCESS_API 248 select HAVE_RELIABLE_STACKTRACE 249 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 250 select HAVE_FUNCTION_ARG_ACCESS_API 251 select MMU_GATHER_RCU_TABLE_FREE 252 select HAVE_RSEQ 253 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 254 select HAVE_STACKPROTECTOR 255 select HAVE_SYSCALL_TRACEPOINTS 256 select HAVE_KPROBES 257 select HAVE_KRETPROBES 258 select HAVE_GENERIC_VDSO 259 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 260 select HOTPLUG_SMT if HOTPLUG_CPU 261 select IRQ_DOMAIN 262 select IRQ_FORCED_THREADING 263 select JUMP_LABEL 264 select KASAN_VMALLOC if KASAN 265 select LOCK_MM_AND_FIND_VMA 266 select MODULES_USE_ELF_RELA 267 select NEED_DMA_MAP_STATE 268 select NEED_SG_DMA_LENGTH 269 select OF 270 select OF_EARLY_FLATTREE 271 select PCI_DOMAINS_GENERIC if PCI 272 select PCI_ECAM if (ACPI && PCI) 273 select PCI_SYSCALL if PCI 274 select POWER_RESET 275 select POWER_SUPPLY 276 select SPARSE_IRQ 277 select SWIOTLB 278 select SYSCTL_EXCEPTION_TRACE 279 select THREAD_INFO_IN_TASK 280 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 281 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 282 select TRACE_IRQFLAGS_SUPPORT 283 select TRACE_IRQFLAGS_NMI_SUPPORT 284 select HAVE_SOFTIRQ_ON_OWN_STACK 285 select USER_STACKTRACE_SUPPORT 286 select VDSO_GETRANDOM 287 select VMAP_STACK 288 help 289 ARM 64-bit (AArch64) Linux support. 290 291config RUSTC_SUPPORTS_ARM64 292 def_bool y 293 depends on CPU_LITTLE_ENDIAN 294 # Shadow call stack is only supported on certain rustc versions. 295 # 296 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 297 # required due to use of the -Zfixed-x18 flag. 298 # 299 # Otherwise, rustc version 1.82+ is required due to use of the 300 # -Zsanitizer=shadow-call-stack flag. 301 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 302 303config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 304 def_bool CC_IS_CLANG 305 # https://github.com/ClangBuiltLinux/linux/issues/1507 306 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 307 308config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 309 def_bool CC_IS_GCC 310 depends on $(cc-option,-fpatchable-function-entry=2) 311 312config 64BIT 313 def_bool y 314 315config MMU 316 def_bool y 317 318config ARM64_CONT_PTE_SHIFT 319 int 320 default 5 if PAGE_SIZE_64KB 321 default 7 if PAGE_SIZE_16KB 322 default 4 323 324config ARM64_CONT_PMD_SHIFT 325 int 326 default 5 if PAGE_SIZE_64KB 327 default 5 if PAGE_SIZE_16KB 328 default 4 329 330config ARCH_MMAP_RND_BITS_MIN 331 default 14 if PAGE_SIZE_64KB 332 default 16 if PAGE_SIZE_16KB 333 default 18 334 335# max bits determined by the following formula: 336# VA_BITS - PTDESC_TABLE_SHIFT 337config ARCH_MMAP_RND_BITS_MAX 338 default 19 if ARM64_VA_BITS=36 339 default 24 if ARM64_VA_BITS=39 340 default 27 if ARM64_VA_BITS=42 341 default 30 if ARM64_VA_BITS=47 342 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 343 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 344 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 345 default 14 if ARM64_64K_PAGES 346 default 16 if ARM64_16K_PAGES 347 default 18 348 349config ARCH_MMAP_RND_COMPAT_BITS_MIN 350 default 7 if ARM64_64K_PAGES 351 default 9 if ARM64_16K_PAGES 352 default 11 353 354config ARCH_MMAP_RND_COMPAT_BITS_MAX 355 default 16 356 357config NO_IOPORT_MAP 358 def_bool y if !PCI 359 360config STACKTRACE_SUPPORT 361 def_bool y 362 363config ILLEGAL_POINTER_VALUE 364 hex 365 default 0xdead000000000000 366 367config LOCKDEP_SUPPORT 368 def_bool y 369 370config GENERIC_BUG 371 def_bool y 372 depends on BUG 373 374config GENERIC_BUG_RELATIVE_POINTERS 375 def_bool y 376 depends on GENERIC_BUG 377 378config GENERIC_HWEIGHT 379 def_bool y 380 381config GENERIC_CSUM 382 def_bool y 383 384config GENERIC_CALIBRATE_DELAY 385 def_bool y 386 387config SMP 388 def_bool y 389 390config KERNEL_MODE_NEON 391 def_bool y 392 393config FIX_EARLYCON_MEM 394 def_bool y 395 396config PGTABLE_LEVELS 397 int 398 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 399 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 400 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 401 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 402 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 403 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 404 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 405 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 406 407config ARCH_SUPPORTS_UPROBES 408 def_bool y 409 410config ARCH_PROC_KCORE_TEXT 411 def_bool y 412 413config BROKEN_GAS_INST 414 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 415 416config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 417 bool 418 # Clang's __builtin_return_address() strips the PAC since 12.0.0 419 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 420 default y if CC_IS_CLANG 421 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 422 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 423 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 424 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 425 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 426 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 427 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 428 default n 429 430config KASAN_SHADOW_OFFSET 431 hex 432 depends on KASAN_GENERIC || KASAN_SW_TAGS 433 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 434 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 435 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 436 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 437 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 438 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 439 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 440 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 441 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 442 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 443 default 0xffffffffffffffff 444 445config UNWIND_TABLES 446 bool 447 448source "arch/arm64/Kconfig.platforms" 449 450menu "Kernel Features" 451 452menu "ARM errata workarounds via the alternatives framework" 453 454config AMPERE_ERRATUM_AC03_CPU_38 455 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 456 default y 457 help 458 This option adds an alternative code sequence to work around Ampere 459 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 460 461 The affected design reports FEAT_HAFDBS as not implemented in 462 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 463 as required by the architecture. The unadvertised HAFDBS 464 implementation suffers from an additional erratum where hardware 465 A/D updates can occur after a PTE has been marked invalid. 466 467 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 468 which avoids enabling unadvertised hardware Access Flag management 469 at stage-2. 470 471 If unsure, say Y. 472 473config AMPERE_ERRATUM_AC04_CPU_23 474 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 475 default y 476 help 477 This option adds an alternative code sequence to work around Ampere 478 errata AC04_CPU_23 on AmpereOne. 479 480 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 481 data addresses initiated by load/store instructions. Only 482 instruction initiated translations are vulnerable, not translations 483 from prefetches for example. A DSB before the store to HCR_EL2 is 484 sufficient to prevent older instructions from hitting the window 485 for corruption, and an ISB after is sufficient to prevent younger 486 instructions from hitting the window for corruption. 487 488 If unsure, say Y. 489 490config ARM64_WORKAROUND_CLEAN_CACHE 491 bool 492 493config ARM64_ERRATUM_826319 494 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 495 default y 496 select ARM64_WORKAROUND_CLEAN_CACHE 497 help 498 This option adds an alternative code sequence to work around ARM 499 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 500 AXI master interface and an L2 cache. 501 502 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 503 and is unable to accept a certain write via this interface, it will 504 not progress on read data presented on the read data channel and the 505 system can deadlock. 506 507 The workaround promotes data cache clean instructions to 508 data cache clean-and-invalidate. 509 Please note that this does not necessarily enable the workaround, 510 as it depends on the alternative framework, which will only patch 511 the kernel if an affected CPU is detected. 512 513 If unsure, say Y. 514 515config ARM64_ERRATUM_827319 516 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 517 default y 518 select ARM64_WORKAROUND_CLEAN_CACHE 519 help 520 This option adds an alternative code sequence to work around ARM 521 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 522 master interface and an L2 cache. 523 524 Under certain conditions this erratum can cause a clean line eviction 525 to occur at the same time as another transaction to the same address 526 on the AMBA 5 CHI interface, which can cause data corruption if the 527 interconnect reorders the two transactions. 528 529 The workaround promotes data cache clean instructions to 530 data cache clean-and-invalidate. 531 Please note that this does not necessarily enable the workaround, 532 as it depends on the alternative framework, which will only patch 533 the kernel if an affected CPU is detected. 534 535 If unsure, say Y. 536 537config ARM64_ERRATUM_824069 538 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 539 default y 540 select ARM64_WORKAROUND_CLEAN_CACHE 541 help 542 This option adds an alternative code sequence to work around ARM 543 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 544 to a coherent interconnect. 545 546 If a Cortex-A53 processor is executing a store or prefetch for 547 write instruction at the same time as a processor in another 548 cluster is executing a cache maintenance operation to the same 549 address, then this erratum might cause a clean cache line to be 550 incorrectly marked as dirty. 551 552 The workaround promotes data cache clean instructions to 553 data cache clean-and-invalidate. 554 Please note that this option does not necessarily enable the 555 workaround, as it depends on the alternative framework, which will 556 only patch the kernel if an affected CPU is detected. 557 558 If unsure, say Y. 559 560config ARM64_ERRATUM_819472 561 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 562 default y 563 select ARM64_WORKAROUND_CLEAN_CACHE 564 help 565 This option adds an alternative code sequence to work around ARM 566 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 567 present when it is connected to a coherent interconnect. 568 569 If the processor is executing a load and store exclusive sequence at 570 the same time as a processor in another cluster is executing a cache 571 maintenance operation to the same address, then this erratum might 572 cause data corruption. 573 574 The workaround promotes data cache clean instructions to 575 data cache clean-and-invalidate. 576 Please note that this does not necessarily enable the workaround, 577 as it depends on the alternative framework, which will only patch 578 the kernel if an affected CPU is detected. 579 580 If unsure, say Y. 581 582config ARM64_ERRATUM_832075 583 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 584 default y 585 help 586 This option adds an alternative code sequence to work around ARM 587 erratum 832075 on Cortex-A57 parts up to r1p2. 588 589 Affected Cortex-A57 parts might deadlock when exclusive load/store 590 instructions to Write-Back memory are mixed with Device loads. 591 592 The workaround is to promote device loads to use Load-Acquire 593 semantics. 594 Please note that this does not necessarily enable the workaround, 595 as it depends on the alternative framework, which will only patch 596 the kernel if an affected CPU is detected. 597 598 If unsure, say Y. 599 600config ARM64_ERRATUM_834220 601 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 602 depends on KVM 603 help 604 This option adds an alternative code sequence to work around ARM 605 erratum 834220 on Cortex-A57 parts up to r1p2. 606 607 Affected Cortex-A57 parts might report a Stage 2 translation 608 fault as the result of a Stage 1 fault for load crossing a 609 page boundary when there is a permission or device memory 610 alignment fault at Stage 1 and a translation fault at Stage 2. 611 612 The workaround is to verify that the Stage 1 translation 613 doesn't generate a fault before handling the Stage 2 fault. 614 Please note that this does not necessarily enable the workaround, 615 as it depends on the alternative framework, which will only patch 616 the kernel if an affected CPU is detected. 617 618 If unsure, say N. 619 620config ARM64_ERRATUM_1742098 621 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 622 depends on COMPAT 623 default y 624 help 625 This option removes the AES hwcap for aarch32 user-space to 626 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 627 628 Affected parts may corrupt the AES state if an interrupt is 629 taken between a pair of AES instructions. These instructions 630 are only present if the cryptography extensions are present. 631 All software should have a fallback implementation for CPUs 632 that don't implement the cryptography extensions. 633 634 If unsure, say Y. 635 636config ARM64_ERRATUM_845719 637 bool "Cortex-A53: 845719: a load might read incorrect data" 638 depends on COMPAT 639 default y 640 help 641 This option adds an alternative code sequence to work around ARM 642 erratum 845719 on Cortex-A53 parts up to r0p4. 643 644 When running a compat (AArch32) userspace on an affected Cortex-A53 645 part, a load at EL0 from a virtual address that matches the bottom 32 646 bits of the virtual address used by a recent load at (AArch64) EL1 647 might return incorrect data. 648 649 The workaround is to write the contextidr_el1 register on exception 650 return to a 32-bit task. 651 Please note that this does not necessarily enable the workaround, 652 as it depends on the alternative framework, which will only patch 653 the kernel if an affected CPU is detected. 654 655 If unsure, say Y. 656 657config ARM64_ERRATUM_843419 658 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 659 default y 660 help 661 This option links the kernel with '--fix-cortex-a53-843419' and 662 enables PLT support to replace certain ADRP instructions, which can 663 cause subsequent memory accesses to use an incorrect address on 664 Cortex-A53 parts up to r0p4. 665 666 If unsure, say Y. 667 668config ARM64_ERRATUM_1024718 669 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 670 default y 671 help 672 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 673 674 Affected Cortex-A55 cores (all revisions) could cause incorrect 675 update of the hardware dirty bit when the DBM/AP bits are updated 676 without a break-before-make. The workaround is to disable the usage 677 of hardware DBM locally on the affected cores. CPUs not affected by 678 this erratum will continue to use the feature. 679 680 If unsure, say Y. 681 682config ARM64_ERRATUM_1418040 683 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 684 default y 685 depends on COMPAT 686 help 687 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 688 errata 1188873 and 1418040. 689 690 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 691 cause register corruption when accessing the timer registers 692 from AArch32 userspace. 693 694 If unsure, say Y. 695 696config ARM64_WORKAROUND_SPECULATIVE_AT 697 bool 698 699config ARM64_ERRATUM_1165522 700 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 701 default y 702 select ARM64_WORKAROUND_SPECULATIVE_AT 703 help 704 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 705 706 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 707 corrupted TLBs by speculating an AT instruction during a guest 708 context switch. 709 710 If unsure, say Y. 711 712config ARM64_ERRATUM_1319367 713 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 714 default y 715 select ARM64_WORKAROUND_SPECULATIVE_AT 716 help 717 This option adds work arounds for ARM Cortex-A57 erratum 1319537 718 and A72 erratum 1319367 719 720 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 721 speculating an AT instruction during a guest context switch. 722 723 If unsure, say Y. 724 725config ARM64_ERRATUM_1530923 726 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 727 default y 728 select ARM64_WORKAROUND_SPECULATIVE_AT 729 help 730 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 731 732 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 733 corrupted TLBs by speculating an AT instruction during a guest 734 context switch. 735 736 If unsure, say Y. 737 738config ARM64_WORKAROUND_REPEAT_TLBI 739 bool 740 741config ARM64_ERRATUM_2441007 742 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 743 select ARM64_WORKAROUND_REPEAT_TLBI 744 help 745 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 746 747 Under very rare circumstances, affected Cortex-A55 CPUs 748 may not handle a race between a break-before-make sequence on one 749 CPU, and another CPU accessing the same page. This could allow a 750 store to a page that has been unmapped. 751 752 Work around this by adding the affected CPUs to the list that needs 753 TLB sequences to be done twice. 754 755 If unsure, say N. 756 757config ARM64_ERRATUM_1286807 758 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 759 select ARM64_WORKAROUND_REPEAT_TLBI 760 help 761 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 762 763 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 764 address for a cacheable mapping of a location is being 765 accessed by a core while another core is remapping the virtual 766 address to a new physical page using the recommended 767 break-before-make sequence, then under very rare circumstances 768 TLBI+DSB completes before a read using the translation being 769 invalidated has been observed by other observers. The 770 workaround repeats the TLBI+DSB operation. 771 772 If unsure, say N. 773 774config ARM64_ERRATUM_1463225 775 bool "Cortex-A76: Software Step might prevent interrupt recognition" 776 default y 777 help 778 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 779 780 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 781 of a system call instruction (SVC) can prevent recognition of 782 subsequent interrupts when software stepping is disabled in the 783 exception handler of the system call and either kernel debugging 784 is enabled or VHE is in use. 785 786 Work around the erratum by triggering a dummy step exception 787 when handling a system call from a task that is being stepped 788 in a VHE configuration of the kernel. 789 790 If unsure, say Y. 791 792config ARM64_ERRATUM_1542419 793 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 794 help 795 This option adds a workaround for ARM Neoverse-N1 erratum 796 1542419. 797 798 Affected Neoverse-N1 cores could execute a stale instruction when 799 modified by another CPU. The workaround depends on a firmware 800 counterpart. 801 802 Workaround the issue by hiding the DIC feature from EL0. This 803 forces user-space to perform cache maintenance. 804 805 If unsure, say N. 806 807config ARM64_ERRATUM_1508412 808 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 809 default y 810 help 811 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 812 813 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 814 of a store-exclusive or read of PAR_EL1 and a load with device or 815 non-cacheable memory attributes. The workaround depends on a firmware 816 counterpart. 817 818 KVM guests must also have the workaround implemented or they can 819 deadlock the system. 820 821 Work around the issue by inserting DMB SY barriers around PAR_EL1 822 register reads and warning KVM users. The DMB barrier is sufficient 823 to prevent a speculative PAR_EL1 read. 824 825 If unsure, say Y. 826 827config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 828 bool 829 830config ARM64_ERRATUM_2051678 831 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 832 default y 833 help 834 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 835 Affected Cortex-A510 might not respect the ordering rules for 836 hardware update of the page table's dirty bit. The workaround 837 is to not enable the feature on affected CPUs. 838 839 If unsure, say Y. 840 841config ARM64_ERRATUM_2077057 842 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 843 default y 844 help 845 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 846 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 847 expected, but a Pointer Authentication trap is taken instead. The 848 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 849 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 850 851 This can only happen when EL2 is stepping EL1. 852 853 When these conditions occur, the SPSR_EL2 value is unchanged from the 854 previous guest entry, and can be restored from the in-memory copy. 855 856 If unsure, say Y. 857 858config ARM64_ERRATUM_2658417 859 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 860 default y 861 help 862 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 863 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 864 BFMMLA or VMMLA instructions in rare circumstances when a pair of 865 A510 CPUs are using shared neon hardware. As the sharing is not 866 discoverable by the kernel, hide the BF16 HWCAP to indicate that 867 user-space should not be using these instructions. 868 869 If unsure, say Y. 870 871config ARM64_ERRATUM_2119858 872 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 873 default y 874 depends on CORESIGHT_TRBE 875 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 876 help 877 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 878 879 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 880 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 881 the event of a WRAP event. 882 883 Work around the issue by always making sure we move the TRBPTR_EL1 by 884 256 bytes before enabling the buffer and filling the first 256 bytes of 885 the buffer with ETM ignore packets upon disabling. 886 887 If unsure, say Y. 888 889config ARM64_ERRATUM_2139208 890 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 891 default y 892 depends on CORESIGHT_TRBE 893 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 894 help 895 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 896 897 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 898 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 899 the event of a WRAP event. 900 901 Work around the issue by always making sure we move the TRBPTR_EL1 by 902 256 bytes before enabling the buffer and filling the first 256 bytes of 903 the buffer with ETM ignore packets upon disabling. 904 905 If unsure, say Y. 906 907config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 908 bool 909 910config ARM64_ERRATUM_2054223 911 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 912 default y 913 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 914 help 915 Enable workaround for ARM Cortex-A710 erratum 2054223 916 917 Affected cores may fail to flush the trace data on a TSB instruction, when 918 the PE is in trace prohibited state. This will cause losing a few bytes 919 of the trace cached. 920 921 Workaround is to issue two TSB consecutively on affected cores. 922 923 If unsure, say Y. 924 925config ARM64_ERRATUM_2067961 926 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 927 default y 928 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 929 help 930 Enable workaround for ARM Neoverse-N2 erratum 2067961 931 932 Affected cores may fail to flush the trace data on a TSB instruction, when 933 the PE is in trace prohibited state. This will cause losing a few bytes 934 of the trace cached. 935 936 Workaround is to issue two TSB consecutively on affected cores. 937 938 If unsure, say Y. 939 940config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 941 bool 942 943config ARM64_ERRATUM_2253138 944 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 945 depends on CORESIGHT_TRBE 946 default y 947 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 948 help 949 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 950 951 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 952 for TRBE. Under some conditions, the TRBE might generate a write to the next 953 virtually addressed page following the last page of the TRBE address space 954 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 955 956 Work around this in the driver by always making sure that there is a 957 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 958 959 If unsure, say Y. 960 961config ARM64_ERRATUM_2224489 962 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 963 depends on CORESIGHT_TRBE 964 default y 965 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 966 help 967 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 968 969 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 970 for TRBE. Under some conditions, the TRBE might generate a write to the next 971 virtually addressed page following the last page of the TRBE address space 972 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 973 974 Work around this in the driver by always making sure that there is a 975 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 976 977 If unsure, say Y. 978 979config ARM64_ERRATUM_2441009 980 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 981 select ARM64_WORKAROUND_REPEAT_TLBI 982 help 983 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 984 985 Under very rare circumstances, affected Cortex-A510 CPUs 986 may not handle a race between a break-before-make sequence on one 987 CPU, and another CPU accessing the same page. This could allow a 988 store to a page that has been unmapped. 989 990 Work around this by adding the affected CPUs to the list that needs 991 TLB sequences to be done twice. 992 993 If unsure, say N. 994 995config ARM64_ERRATUM_2064142 996 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 997 depends on CORESIGHT_TRBE 998 default y 999 help 1000 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 1001 1002 Affected Cortex-A510 core might fail to write into system registers after the 1003 TRBE has been disabled. Under some conditions after the TRBE has been disabled 1004 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 1005 and TRBTRG_EL1 will be ignored and will not be effected. 1006 1007 Work around this in the driver by executing TSB CSYNC and DSB after collection 1008 is stopped and before performing a system register write to one of the affected 1009 registers. 1010 1011 If unsure, say Y. 1012 1013config ARM64_ERRATUM_2038923 1014 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1015 depends on CORESIGHT_TRBE 1016 default y 1017 help 1018 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1019 1020 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1021 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1022 might be corrupted. This happens after TRBE buffer has been enabled by setting 1023 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1024 execution changes from a context, in which trace is prohibited to one where it 1025 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1026 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1027 the trace buffer state might be corrupted. 1028 1029 Work around this in the driver by preventing an inconsistent view of whether the 1030 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1031 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1032 two ISB instructions if no ERET is to take place. 1033 1034 If unsure, say Y. 1035 1036config ARM64_ERRATUM_1902691 1037 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1038 depends on CORESIGHT_TRBE 1039 default y 1040 help 1041 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1042 1043 Affected Cortex-A510 core might cause trace data corruption, when being written 1044 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1045 trace data. 1046 1047 Work around this problem in the driver by just preventing TRBE initialization on 1048 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1049 on such implementations. This will cover the kernel for any firmware that doesn't 1050 do this already. 1051 1052 If unsure, say Y. 1053 1054config ARM64_ERRATUM_2457168 1055 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1056 depends on ARM64_AMU_EXTN 1057 default y 1058 help 1059 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1060 1061 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1062 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1063 incorrectly giving a significantly higher output value. 1064 1065 Work around this problem by returning 0 when reading the affected counter in 1066 key locations that results in disabling all users of this counter. This effect 1067 is the same to firmware disabling affected counters. 1068 1069 If unsure, say Y. 1070 1071config ARM64_ERRATUM_2645198 1072 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1073 default y 1074 help 1075 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1076 1077 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1078 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1079 next instruction abort caused by permission fault. 1080 1081 Only user-space does executable to non-executable permission transition via 1082 mprotect() system call. Workaround the problem by doing a break-before-make 1083 TLB invalidation, for all changes to executable user space mappings. 1084 1085 If unsure, say Y. 1086 1087config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1088 bool 1089 1090config ARM64_ERRATUM_2966298 1091 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1092 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1093 default y 1094 help 1095 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1096 1097 On an affected Cortex-A520 core, a speculatively executed unprivileged 1098 load might leak data from a privileged level via a cache side channel. 1099 1100 Work around this problem by executing a TLBI before returning to EL0. 1101 1102 If unsure, say Y. 1103 1104config ARM64_ERRATUM_3117295 1105 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1106 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1107 default y 1108 help 1109 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1110 1111 On an affected Cortex-A510 core, a speculatively executed unprivileged 1112 load might leak data from a privileged level via a cache side channel. 1113 1114 Work around this problem by executing a TLBI before returning to EL0. 1115 1116 If unsure, say Y. 1117 1118config ARM64_ERRATUM_3194386 1119 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1120 default y 1121 help 1122 This option adds the workaround for the following errata: 1123 1124 * ARM Cortex-A76 erratum 3324349 1125 * ARM Cortex-A77 erratum 3324348 1126 * ARM Cortex-A78 erratum 3324344 1127 * ARM Cortex-A78C erratum 3324346 1128 * ARM Cortex-A78C erratum 3324347 1129 * ARM Cortex-A710 erratam 3324338 1130 * ARM Cortex-A715 errartum 3456084 1131 * ARM Cortex-A720 erratum 3456091 1132 * ARM Cortex-A725 erratum 3456106 1133 * ARM Cortex-X1 erratum 3324344 1134 * ARM Cortex-X1C erratum 3324346 1135 * ARM Cortex-X2 erratum 3324338 1136 * ARM Cortex-X3 erratum 3324335 1137 * ARM Cortex-X4 erratum 3194386 1138 * ARM Cortex-X925 erratum 3324334 1139 * ARM Neoverse-N1 erratum 3324349 1140 * ARM Neoverse N2 erratum 3324339 1141 * ARM Neoverse-N3 erratum 3456111 1142 * ARM Neoverse-V1 erratum 3324341 1143 * ARM Neoverse V2 erratum 3324336 1144 * ARM Neoverse-V3 erratum 3312417 1145 * ARM Neoverse-V3AE erratum 3312417 1146 1147 On affected cores "MSR SSBS, #0" instructions may not affect 1148 subsequent speculative instructions, which may permit unexepected 1149 speculative store bypassing. 1150 1151 Work around this problem by placing a Speculation Barrier (SB) or 1152 Instruction Synchronization Barrier (ISB) after kernel changes to 1153 SSBS. The presence of the SSBS special-purpose register is hidden 1154 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1155 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1156 1157 If unsure, say Y. 1158 1159config ARM64_ERRATUM_4311569 1160 bool "SI L1: 4311569: workaround for premature CMO completion erratum" 1161 default y 1162 help 1163 This option adds the workaround for ARM SI L1 erratum 4311569. 1164 1165 The erratum of SI L1 can cause an early response to a combined write 1166 and cache maintenance operation (WR+CMO) before the operation is fully 1167 completed to the Point of Serialization (POS). 1168 This can result in a non-I/O coherent agent observing stale data, 1169 potentially leading to system instability or incorrect behavior. 1170 1171 Enabling this option implements a software workaround by inserting a 1172 second loop of Cache Maintenance Operation (CMO) immediately following the 1173 end of function to do CMOs. This ensures that the data is correctly serialized 1174 before the buffer is handed off to a non-coherent agent. 1175 1176 If unsure, say Y. 1177 1178config CAVIUM_ERRATUM_22375 1179 bool "Cavium erratum 22375, 24313" 1180 default y 1181 help 1182 Enable workaround for errata 22375 and 24313. 1183 1184 This implements two gicv3-its errata workarounds for ThunderX. Both 1185 with a small impact affecting only ITS table allocation. 1186 1187 erratum 22375: only alloc 8MB table size 1188 erratum 24313: ignore memory access type 1189 1190 The fixes are in ITS initialization and basically ignore memory access 1191 type and table size provided by the TYPER and BASER registers. 1192 1193 If unsure, say Y. 1194 1195config CAVIUM_ERRATUM_23144 1196 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1197 depends on NUMA 1198 default y 1199 help 1200 ITS SYNC command hang for cross node io and collections/cpu mapping. 1201 1202 If unsure, say Y. 1203 1204config CAVIUM_ERRATUM_23154 1205 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1206 default y 1207 help 1208 The ThunderX GICv3 implementation requires a modified version for 1209 reading the IAR status to ensure data synchronization 1210 (access to icc_iar1_el1 is not sync'ed before and after). 1211 1212 It also suffers from erratum 38545 (also present on Marvell's 1213 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1214 spuriously presented to the CPU interface. 1215 1216 If unsure, say Y. 1217 1218config CAVIUM_ERRATUM_27456 1219 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1220 default y 1221 help 1222 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1223 instructions may cause the icache to become corrupted if it 1224 contains data for a non-current ASID. The fix is to 1225 invalidate the icache when changing the mm context. 1226 1227 If unsure, say Y. 1228 1229config CAVIUM_ERRATUM_30115 1230 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1231 default y 1232 help 1233 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1234 1.2, and T83 Pass 1.0, KVM guest execution may disable 1235 interrupts in host. Trapping both GICv3 group-0 and group-1 1236 accesses sidesteps the issue. 1237 1238 If unsure, say Y. 1239 1240config CAVIUM_TX2_ERRATUM_219 1241 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1242 default y 1243 help 1244 On Cavium ThunderX2, a load, store or prefetch instruction between a 1245 TTBR update and the corresponding context synchronizing operation can 1246 cause a spurious Data Abort to be delivered to any hardware thread in 1247 the CPU core. 1248 1249 Work around the issue by avoiding the problematic code sequence and 1250 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1251 trap handler performs the corresponding register access, skips the 1252 instruction and ensures context synchronization by virtue of the 1253 exception return. 1254 1255 If unsure, say Y. 1256 1257config FUJITSU_ERRATUM_010001 1258 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1259 default y 1260 help 1261 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1262 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1263 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1264 This fault occurs under a specific hardware condition when a 1265 load/store instruction performs an address translation using: 1266 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1267 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1268 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1269 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1270 1271 The workaround is to ensure these bits are clear in TCR_ELx. 1272 The workaround only affects the Fujitsu-A64FX. 1273 1274 If unsure, say Y. 1275 1276config HISILICON_ERRATUM_161600802 1277 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1278 default y 1279 help 1280 The HiSilicon Hip07 SoC uses the wrong redistributor base 1281 when issued ITS commands such as VMOVP and VMAPP, and requires 1282 a 128kB offset to be applied to the target address in this commands. 1283 1284 If unsure, say Y. 1285 1286config HISILICON_ERRATUM_162100801 1287 bool "Hip09 162100801 erratum support" 1288 default y 1289 help 1290 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1291 during unmapping operation, which will cause some vSGIs lost. 1292 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1293 after VMOVP. 1294 1295 If unsure, say Y. 1296 1297config QCOM_FALKOR_ERRATUM_1003 1298 bool "Falkor E1003: Incorrect translation due to ASID change" 1299 default y 1300 help 1301 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1302 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1303 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1304 then only for entries in the walk cache, since the leaf translation 1305 is unchanged. Work around the erratum by invalidating the walk cache 1306 entries for the trampoline before entering the kernel proper. 1307 1308config QCOM_FALKOR_ERRATUM_1009 1309 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1310 default y 1311 select ARM64_WORKAROUND_REPEAT_TLBI 1312 help 1313 On Falkor v1, the CPU may prematurely complete a DSB following a 1314 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1315 one more time to fix the issue. 1316 1317 If unsure, say Y. 1318 1319config QCOM_QDF2400_ERRATUM_0065 1320 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1321 default y 1322 help 1323 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1324 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1325 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1326 1327 If unsure, say Y. 1328 1329config QCOM_FALKOR_ERRATUM_E1041 1330 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1331 default y 1332 help 1333 Falkor CPU may speculatively fetch instructions from an improper 1334 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1335 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1336 1337 If unsure, say Y. 1338 1339config NVIDIA_CARMEL_CNP_ERRATUM 1340 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1341 default y 1342 help 1343 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1344 invalidate shared TLB entries installed by a different core, as it would 1345 on standard ARM cores. 1346 1347 If unsure, say Y. 1348 1349config ROCKCHIP_ERRATUM_3568002 1350 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1351 default y 1352 help 1353 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1354 addressing limited to the first 32bit of physical address space. 1355 1356 If unsure, say Y. 1357 1358config ROCKCHIP_ERRATUM_3588001 1359 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1360 default y 1361 help 1362 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1363 This means, that its sharability feature may not be used, even though it 1364 is supported by the IP itself. 1365 1366 If unsure, say Y. 1367 1368config SOCIONEXT_SYNQUACER_PREITS 1369 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1370 default y 1371 help 1372 Socionext Synquacer SoCs implement a separate h/w block to generate 1373 MSI doorbell writes with non-zero values for the device ID. 1374 1375 If unsure, say Y. 1376 1377endmenu # "ARM errata workarounds via the alternatives framework" 1378 1379choice 1380 prompt "Page size" 1381 default ARM64_4K_PAGES 1382 help 1383 Page size (translation granule) configuration. 1384 1385config ARM64_4K_PAGES 1386 bool "4KB" 1387 select HAVE_PAGE_SIZE_4KB 1388 help 1389 This feature enables 4KB pages support. 1390 1391config ARM64_16K_PAGES 1392 bool "16KB" 1393 select HAVE_PAGE_SIZE_16KB 1394 help 1395 The system will use 16KB pages support. AArch32 emulation 1396 requires applications compiled with 16K (or a multiple of 16K) 1397 aligned segments. 1398 1399config ARM64_64K_PAGES 1400 bool "64KB" 1401 select HAVE_PAGE_SIZE_64KB 1402 help 1403 This feature enables 64KB pages support (4KB by default) 1404 allowing only two levels of page tables and faster TLB 1405 look-up. AArch32 emulation requires applications compiled 1406 with 64K aligned segments. 1407 1408endchoice 1409 1410choice 1411 prompt "Virtual address space size" 1412 default ARM64_VA_BITS_52 1413 help 1414 Allows choosing one of multiple possible virtual address 1415 space sizes. The level of translation table is determined by 1416 a combination of page size and virtual address space size. 1417 1418config ARM64_VA_BITS_36 1419 bool "36-bit" if EXPERT 1420 depends on PAGE_SIZE_16KB 1421 1422config ARM64_VA_BITS_39 1423 bool "39-bit" 1424 depends on PAGE_SIZE_4KB 1425 1426config ARM64_VA_BITS_42 1427 bool "42-bit" 1428 depends on PAGE_SIZE_64KB 1429 1430config ARM64_VA_BITS_47 1431 bool "47-bit" 1432 depends on PAGE_SIZE_16KB 1433 1434config ARM64_VA_BITS_48 1435 bool "48-bit" 1436 1437config ARM64_VA_BITS_52 1438 bool "52-bit" 1439 help 1440 Enable 52-bit virtual addressing for userspace when explicitly 1441 requested via a hint to mmap(). The kernel will also use 52-bit 1442 virtual addresses for its own mappings (provided HW support for 1443 this feature is available, otherwise it reverts to 48-bit). 1444 1445 NOTE: Enabling 52-bit virtual addressing in conjunction with 1446 ARMv8.3 Pointer Authentication will result in the PAC being 1447 reduced from 7 bits to 3 bits, which may have a significant 1448 impact on its susceptibility to brute-force attacks. 1449 1450 If unsure, select 48-bit virtual addressing instead. 1451 1452endchoice 1453 1454config ARM64_FORCE_52BIT 1455 bool "Force 52-bit virtual addresses for userspace" 1456 depends on ARM64_VA_BITS_52 && EXPERT 1457 help 1458 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1459 to maintain compatibility with older software by providing 48-bit VAs 1460 unless a hint is supplied to mmap. 1461 1462 This configuration option disables the 48-bit compatibility logic, and 1463 forces all userspace addresses to be 52-bit on HW that supports it. One 1464 should only enable this configuration option for stress testing userspace 1465 memory management code. If unsure say N here. 1466 1467config ARM64_VA_BITS 1468 int 1469 default 36 if ARM64_VA_BITS_36 1470 default 39 if ARM64_VA_BITS_39 1471 default 42 if ARM64_VA_BITS_42 1472 default 47 if ARM64_VA_BITS_47 1473 default 48 if ARM64_VA_BITS_48 1474 default 52 if ARM64_VA_BITS_52 1475 1476choice 1477 prompt "Physical address space size" 1478 default ARM64_PA_BITS_48 1479 help 1480 Choose the maximum physical address range that the kernel will 1481 support. 1482 1483config ARM64_PA_BITS_48 1484 bool "48-bit" 1485 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1486 1487config ARM64_PA_BITS_52 1488 bool "52-bit" 1489 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1490 help 1491 Enable support for a 52-bit physical address space, introduced as 1492 part of the ARMv8.2-LPA extension. 1493 1494 With this enabled, the kernel will also continue to work on CPUs that 1495 do not support ARMv8.2-LPA, but with some added memory overhead (and 1496 minor performance overhead). 1497 1498endchoice 1499 1500config ARM64_PA_BITS 1501 int 1502 default 48 if ARM64_PA_BITS_48 1503 default 52 if ARM64_PA_BITS_52 1504 1505config ARM64_LPA2 1506 def_bool y 1507 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1508 1509choice 1510 prompt "Endianness" 1511 default CPU_LITTLE_ENDIAN 1512 help 1513 Select the endianness of data accesses performed by the CPU. Userspace 1514 applications will need to be compiled and linked for the endianness 1515 that is selected here. 1516 1517config CPU_BIG_ENDIAN 1518 bool "Build big-endian kernel" 1519 depends on BROKEN 1520 help 1521 Say Y if you plan on running a kernel with a big-endian userspace. 1522 1523config CPU_LITTLE_ENDIAN 1524 bool "Build little-endian kernel" 1525 help 1526 Say Y if you plan on running a kernel with a little-endian userspace. 1527 This is usually the case for distributions targeting arm64. 1528 1529endchoice 1530 1531config NR_CPUS 1532 int "Maximum number of CPUs (2-4096)" 1533 range 2 4096 1534 default "512" 1535 1536config HOTPLUG_CPU 1537 bool "Support for hot-pluggable CPUs" 1538 select GENERIC_IRQ_MIGRATION 1539 help 1540 Say Y here to experiment with turning CPUs off and on. CPUs 1541 can be controlled through /sys/devices/system/cpu. 1542 1543# Common NUMA Features 1544config NUMA 1545 bool "NUMA Memory Allocation and Scheduler Support" 1546 select GENERIC_ARCH_NUMA 1547 select OF_NUMA 1548 select HAVE_SETUP_PER_CPU_AREA 1549 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1550 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1551 select USE_PERCPU_NUMA_NODE_ID 1552 help 1553 Enable NUMA (Non-Uniform Memory Access) support. 1554 1555 The kernel will try to allocate memory used by a CPU on the 1556 local memory of the CPU and add some more 1557 NUMA awareness to the kernel. 1558 1559config NODES_SHIFT 1560 int "Maximum NUMA Nodes (as a power of 2)" 1561 range 1 10 1562 default "4" 1563 depends on NUMA 1564 help 1565 Specify the maximum number of NUMA Nodes available on the target 1566 system. Increases memory reserved to accommodate various tables. 1567 1568source "kernel/Kconfig.hz" 1569 1570config ARCH_SPARSEMEM_ENABLE 1571 def_bool y 1572 select SPARSEMEM_VMEMMAP_ENABLE 1573 1574config HW_PERF_EVENTS 1575 def_bool y 1576 depends on ARM_PMU 1577 1578# Supported by clang >= 7.0 or GCC >= 12.0.0 1579config CC_HAVE_SHADOW_CALL_STACK 1580 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1581 1582config PARAVIRT 1583 bool "Enable paravirtualization code" 1584 select HAVE_PV_STEAL_CLOCK_GEN 1585 help 1586 This changes the kernel so it can modify itself when it is run 1587 under a hypervisor, potentially improving performance significantly 1588 over full virtualization. 1589 1590config PARAVIRT_TIME_ACCOUNTING 1591 bool "Paravirtual steal time accounting" 1592 select PARAVIRT 1593 help 1594 Select this option to enable fine granularity task steal time 1595 accounting. Time spent executing other tasks in parallel with 1596 the current vCPU is discounted from the vCPU power. To account for 1597 that, there can be a small performance impact. 1598 1599 If in doubt, say N here. 1600 1601config ARCH_SUPPORTS_KEXEC 1602 def_bool PM_SLEEP_SMP 1603 1604config ARCH_SUPPORTS_KEXEC_FILE 1605 def_bool y 1606 1607config ARCH_SELECTS_KEXEC_FILE 1608 def_bool y 1609 depends on KEXEC_FILE 1610 select HAVE_IMA_KEXEC if IMA 1611 1612config ARCH_SUPPORTS_KEXEC_SIG 1613 def_bool y 1614 1615config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1616 def_bool y 1617 1618config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1619 def_bool y 1620 1621config ARCH_SUPPORTS_KEXEC_HANDOVER 1622 def_bool y 1623 1624config ARCH_SUPPORTS_CRASH_DUMP 1625 def_bool y 1626 1627config ARCH_DEFAULT_CRASH_DUMP 1628 def_bool y 1629 1630config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1631 def_bool CRASH_RESERVE 1632 1633config TRANS_TABLE 1634 def_bool y 1635 depends on HIBERNATION || KEXEC_CORE 1636 1637config XEN_DOM0 1638 def_bool y 1639 depends on XEN 1640 1641config XEN 1642 bool "Xen guest support on ARM64" 1643 depends on ARM64 && OF 1644 select SWIOTLB_XEN 1645 select PARAVIRT 1646 help 1647 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1648 1649# include/linux/mmzone.h requires the following to be true: 1650# 1651# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1652# 1653# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1654# 1655# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1656# ----+-------------------+--------------+----------------------+-------------------------+ 1657# 4K | 27 | 12 | 15 | 10 | 1658# 16K | 27 | 14 | 13 | 11 | 1659# 64K | 29 | 16 | 13 | 13 | 1660config ARCH_FORCE_MAX_ORDER 1661 int 1662 default "13" if ARM64_64K_PAGES 1663 default "11" if ARM64_16K_PAGES 1664 default "10" 1665 help 1666 The kernel page allocator limits the size of maximal physically 1667 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1668 defines the maximal power of two of number of pages that can be 1669 allocated as a single contiguous block. This option allows 1670 overriding the default setting when ability to allocate very 1671 large blocks of physically contiguous memory is required. 1672 1673 The maximal size of allocation cannot exceed the size of the 1674 section, so the value of MAX_PAGE_ORDER should satisfy 1675 1676 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1677 1678 Don't change if unsure. 1679 1680config UNMAP_KERNEL_AT_EL0 1681 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1682 default y 1683 help 1684 Speculation attacks against some high-performance processors can 1685 be used to bypass MMU permission checks and leak kernel data to 1686 userspace. This can be defended against by unmapping the kernel 1687 when running in userspace, mapping it back in on exception entry 1688 via a trampoline page in the vector table. 1689 1690 If unsure, say Y. 1691 1692config MITIGATE_SPECTRE_BRANCH_HISTORY 1693 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1694 default y 1695 help 1696 Speculation attacks against some high-performance processors can 1697 make use of branch history to influence future speculation. 1698 When taking an exception from user-space, a sequence of branches 1699 or a firmware call overwrites the branch history. 1700 1701config ARM64_SW_TTBR0_PAN 1702 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1703 depends on !KCSAN 1704 help 1705 Enabling this option prevents the kernel from accessing 1706 user-space memory directly by pointing TTBR0_EL1 to a reserved 1707 zeroed area and reserved ASID. The user access routines 1708 restore the valid TTBR0_EL1 temporarily. 1709 1710config ARM64_TAGGED_ADDR_ABI 1711 bool "Enable the tagged user addresses syscall ABI" 1712 default y 1713 help 1714 When this option is enabled, user applications can opt in to a 1715 relaxed ABI via prctl() allowing tagged addresses to be passed 1716 to system calls as pointer arguments. For details, see 1717 Documentation/arch/arm64/tagged-address-abi.rst. 1718 1719menuconfig COMPAT 1720 bool "Kernel support for 32-bit EL0" 1721 depends on ARM64_4K_PAGES || EXPERT 1722 select HAVE_UID16 1723 select OLD_SIGSUSPEND3 1724 select COMPAT_OLD_SIGACTION 1725 help 1726 This option enables support for a 32-bit EL0 running under a 64-bit 1727 kernel at EL1. AArch32-specific components such as system calls, 1728 the user helper functions, VFP support and the ptrace interface are 1729 handled appropriately by the kernel. 1730 1731 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1732 that you will only be able to execute AArch32 binaries that were compiled 1733 with page size aligned segments. 1734 1735 If you want to execute 32-bit userspace applications, say Y. 1736 1737if COMPAT 1738 1739config KUSER_HELPERS 1740 bool "Enable kuser helpers page for 32-bit applications" 1741 default y 1742 help 1743 Warning: disabling this option may break 32-bit user programs. 1744 1745 Provide kuser helpers to compat tasks. The kernel provides 1746 helper code to userspace in read only form at a fixed location 1747 to allow userspace to be independent of the CPU type fitted to 1748 the system. This permits binaries to be run on ARMv4 through 1749 to ARMv8 without modification. 1750 1751 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1752 1753 However, the fixed address nature of these helpers can be used 1754 by ROP (return orientated programming) authors when creating 1755 exploits. 1756 1757 If all of the binaries and libraries which run on your platform 1758 are built specifically for your platform, and make no use of 1759 these helpers, then you can turn this option off to hinder 1760 such exploits. However, in that case, if a binary or library 1761 relying on those helpers is run, it will not function correctly. 1762 1763 Say N here only if you are absolutely certain that you do not 1764 need these helpers; otherwise, the safe option is to say Y. 1765 1766config COMPAT_VDSO 1767 bool "Enable vDSO for 32-bit applications" 1768 depends on !CPU_BIG_ENDIAN 1769 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1770 default y 1771 help 1772 Place in the process address space of 32-bit applications an 1773 ELF shared object providing fast implementations of gettimeofday 1774 and clock_gettime. 1775 1776 You must have a 32-bit build of glibc 2.22 or later for programs 1777 to seamlessly take advantage of this. 1778 1779config THUMB2_COMPAT_VDSO 1780 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1781 depends on COMPAT_VDSO 1782 default y 1783 help 1784 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1785 otherwise with '-marm'. 1786 1787config COMPAT_ALIGNMENT_FIXUPS 1788 bool "Fix up misaligned multi-word loads and stores in user space" 1789 1790menuconfig ARMV8_DEPRECATED 1791 bool "Emulate deprecated/obsolete ARMv8 instructions" 1792 depends on SYSCTL 1793 help 1794 Legacy software support may require certain instructions 1795 that have been deprecated or obsoleted in the architecture. 1796 1797 Enable this config to enable selective emulation of these 1798 features. 1799 1800 If unsure, say Y 1801 1802if ARMV8_DEPRECATED 1803 1804config SWP_EMULATION 1805 bool "Emulate SWP/SWPB instructions" 1806 help 1807 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1808 they are always undefined. Say Y here to enable software 1809 emulation of these instructions for userspace using LDXR/STXR. 1810 This feature can be controlled at runtime with the abi.swp 1811 sysctl which is disabled by default. 1812 1813 In some older versions of glibc [<=2.8] SWP is used during futex 1814 trylock() operations with the assumption that the code will not 1815 be preempted. This invalid assumption may be more likely to fail 1816 with SWP emulation enabled, leading to deadlock of the user 1817 application. 1818 1819 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1820 on an external transaction monitoring block called a global 1821 monitor to maintain update atomicity. If your system does not 1822 implement a global monitor, this option can cause programs that 1823 perform SWP operations to uncached memory to deadlock. 1824 1825 If unsure, say Y 1826 1827config CP15_BARRIER_EMULATION 1828 bool "Emulate CP15 Barrier instructions" 1829 help 1830 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1831 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1832 strongly recommended to use the ISB, DSB, and DMB 1833 instructions instead. 1834 1835 Say Y here to enable software emulation of these 1836 instructions for AArch32 userspace code. When this option is 1837 enabled, CP15 barrier usage is traced which can help 1838 identify software that needs updating. This feature can be 1839 controlled at runtime with the abi.cp15_barrier sysctl. 1840 1841 If unsure, say Y 1842 1843config SETEND_EMULATION 1844 bool "Emulate SETEND instruction" 1845 help 1846 The SETEND instruction alters the data-endianness of the 1847 AArch32 EL0, and is deprecated in ARMv8. 1848 1849 Say Y here to enable software emulation of the instruction 1850 for AArch32 userspace code. This feature can be controlled 1851 at runtime with the abi.setend sysctl. 1852 1853 Note: All the cpus on the system must have mixed endian support at EL0 1854 for this feature to be enabled. If a new CPU - which doesn't support mixed 1855 endian - is hotplugged in after this feature has been enabled, there could 1856 be unexpected results in the applications. 1857 1858 If unsure, say Y 1859endif # ARMV8_DEPRECATED 1860 1861endif # COMPAT 1862 1863menu "ARMv8.1 architectural features" 1864 1865config ARM64_HW_AFDBM 1866 bool "Support for hardware updates of the Access and Dirty page flags" 1867 default y 1868 help 1869 The ARMv8.1 architecture extensions introduce support for 1870 hardware updates of the access and dirty information in page 1871 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1872 capable processors, accesses to pages with PTE_AF cleared will 1873 set this bit instead of raising an access flag fault. 1874 Similarly, writes to read-only pages with the DBM bit set will 1875 clear the read-only bit (AP[2]) instead of raising a 1876 permission fault. 1877 1878 Kernels built with this configuration option enabled continue 1879 to work on pre-ARMv8.1 hardware and the performance impact is 1880 minimal. If unsure, say Y. 1881 1882endmenu # "ARMv8.1 architectural features" 1883 1884menu "ARMv8.2 architectural features" 1885 1886config ARM64_PMEM 1887 bool "Enable support for persistent memory" 1888 select ARCH_HAS_PMEM_API 1889 select ARCH_HAS_UACCESS_FLUSHCACHE 1890 help 1891 Say Y to enable support for the persistent memory API based on the 1892 ARMv8.2 DCPoP feature. 1893 1894 The feature is detected at runtime, and the kernel will use DC CVAC 1895 operations if DC CVAP is not supported (following the behaviour of 1896 DC CVAP itself if the system does not define a point of persistence). 1897 1898config ARM64_RAS_EXTN 1899 bool "Enable support for RAS CPU Extensions" 1900 default y 1901 help 1902 CPUs that support the Reliability, Availability and Serviceability 1903 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1904 errors, classify them and report them to software. 1905 1906 On CPUs with these extensions system software can use additional 1907 barriers to determine if faults are pending and read the 1908 classification from a new set of registers. 1909 1910 Selecting this feature will allow the kernel to use these barriers 1911 and access the new registers if the system supports the extension. 1912 Platform RAS features may additionally depend on firmware support. 1913 1914config ARM64_CNP 1915 bool "Enable support for Common Not Private (CNP) translations" 1916 default y 1917 help 1918 Common Not Private (CNP) allows translation table entries to 1919 be shared between different PEs in the same inner shareable 1920 domain, so the hardware can use this fact to optimise the 1921 caching of such entries in the TLB. 1922 1923 Selecting this option allows the CNP feature to be detected 1924 at runtime, and does not affect PEs that do not implement 1925 this feature. 1926 1927endmenu # "ARMv8.2 architectural features" 1928 1929menu "ARMv8.3 architectural features" 1930 1931config ARM64_PTR_AUTH 1932 bool "Enable support for pointer authentication" 1933 default y 1934 help 1935 Pointer authentication (part of the ARMv8.3 Extensions) provides 1936 instructions for signing and authenticating pointers against secret 1937 keys, which can be used to mitigate Return Oriented Programming (ROP) 1938 and other attacks. 1939 1940 This option enables these instructions at EL0 (i.e. for userspace). 1941 Choosing this option will cause the kernel to initialise secret keys 1942 for each process at exec() time, with these keys being 1943 context-switched along with the process. 1944 1945 The feature is detected at runtime. If the feature is not present in 1946 hardware it will not be advertised to userspace/KVM guest nor will it 1947 be enabled. 1948 1949 If the feature is present on the boot CPU but not on a late CPU, then 1950 the late CPU will be parked. Also, if the boot CPU does not have 1951 address auth and the late CPU has then the late CPU will still boot 1952 but with the feature disabled. On such a system, this option should 1953 not be selected. 1954 1955config ARM64_PTR_AUTH_KERNEL 1956 bool "Use pointer authentication for kernel" 1957 default y 1958 depends on ARM64_PTR_AUTH 1959 # Modern compilers insert a .note.gnu.property section note for PAC 1960 # which is only understood by binutils starting with version 2.33.1. 1961 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1962 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1963 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1964 help 1965 If the compiler supports the -mbranch-protection or 1966 -msign-return-address flag (e.g. GCC 7 or later), then this option 1967 will cause the kernel itself to be compiled with return address 1968 protection. In this case, and if the target hardware is known to 1969 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1970 disabled with minimal loss of protection. 1971 1972 This feature works with FUNCTION_GRAPH_TRACER option only if 1973 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1974 1975config CC_HAS_BRANCH_PROT_PAC_RET 1976 # GCC 9 or later, clang 8 or later 1977 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1978 1979config AS_HAS_CFI_NEGATE_RA_STATE 1980 # binutils 2.34+ 1981 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1982 1983endmenu # "ARMv8.3 architectural features" 1984 1985menu "ARMv8.4 architectural features" 1986 1987config ARM64_AMU_EXTN 1988 bool "Enable support for the Activity Monitors Unit CPU extension" 1989 default y 1990 help 1991 The activity monitors extension is an optional extension introduced 1992 by the ARMv8.4 CPU architecture. This enables support for version 1 1993 of the activity monitors architecture, AMUv1. 1994 1995 To enable the use of this extension on CPUs that implement it, say Y. 1996 1997 Note that for architectural reasons, firmware _must_ implement AMU 1998 support when running on CPUs that present the activity monitors 1999 extension. The required support is present in: 2000 * Version 1.5 and later of the ARM Trusted Firmware 2001 2002 For kernels that have this configuration enabled but boot with broken 2003 firmware, you may need to say N here until the firmware is fixed. 2004 Otherwise you may experience firmware panics or lockups when 2005 accessing the counter registers. Even if you are not observing these 2006 symptoms, the values returned by the register reads might not 2007 correctly reflect reality. Most commonly, the value read will be 0, 2008 indicating that the counter is not enabled. 2009 2010config ARM64_TLB_RANGE 2011 bool "Enable support for tlbi range feature" 2012 default y 2013 help 2014 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2015 range of input addresses. 2016 2017config ARM64_MPAM 2018 bool "Enable support for MPAM" 2019 select ARM64_MPAM_DRIVER if EXPERT # does nothing yet 2020 select ACPI_MPAM if ACPI 2021 help 2022 Memory System Resource Partitioning and Monitoring (MPAM) is an 2023 optional extension to the Arm architecture that allows each 2024 transaction issued to the memory system to be labelled with a 2025 Partition identifier (PARTID) and Performance Monitoring Group 2026 identifier (PMG). 2027 2028 Memory system components, such as the caches, can be configured with 2029 policies to control how much of various physical resources (such as 2030 memory bandwidth or cache memory) the transactions labelled with each 2031 PARTID can consume. Depending on the capabilities of the hardware, 2032 the PARTID and PMG can also be used as filtering criteria to measure 2033 the memory system resource consumption of different parts of a 2034 workload. 2035 2036 Use of this extension requires CPU support, support in the 2037 Memory System Components (MSC), and a description from firmware 2038 of where the MSCs are in the address space. 2039 2040 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2041 2042endmenu # "ARMv8.4 architectural features" 2043 2044menu "ARMv8.5 architectural features" 2045 2046config AS_HAS_ARMV8_5 2047 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2048 2049config ARM64_BTI 2050 bool "Branch Target Identification support" 2051 default y 2052 help 2053 Branch Target Identification (part of the ARMv8.5 Extensions) 2054 provides a mechanism to limit the set of locations to which computed 2055 branch instructions such as BR or BLR can jump. 2056 2057 To make use of BTI on CPUs that support it, say Y. 2058 2059 BTI is intended to provide complementary protection to other control 2060 flow integrity protection mechanisms, such as the Pointer 2061 authentication mechanism provided as part of the ARMv8.3 Extensions. 2062 For this reason, it does not make sense to enable this option without 2063 also enabling support for pointer authentication. Thus, when 2064 enabling this option you should also select ARM64_PTR_AUTH=y. 2065 2066 Userspace binaries must also be specifically compiled to make use of 2067 this mechanism. If you say N here or the hardware does not support 2068 BTI, such binaries can still run, but you get no additional 2069 enforcement of branch destinations. 2070 2071config ARM64_BTI_KERNEL 2072 bool "Use Branch Target Identification for kernel" 2073 default y 2074 depends on ARM64_BTI 2075 depends on ARM64_PTR_AUTH_KERNEL 2076 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2077 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2078 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2079 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2080 depends on !CC_IS_GCC 2081 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2082 help 2083 Build the kernel with Branch Target Identification annotations 2084 and enable enforcement of this for kernel code. When this option 2085 is enabled and the system supports BTI all kernel code including 2086 modular code must have BTI enabled. 2087 2088config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2089 # GCC 9 or later, clang 8 or later 2090 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2091 2092config ARM64_E0PD 2093 bool "Enable support for E0PD" 2094 default y 2095 help 2096 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2097 that EL0 accesses made via TTBR1 always fault in constant time, 2098 providing similar benefits to KASLR as those provided by KPTI, but 2099 with lower overhead and without disrupting legitimate access to 2100 kernel memory such as SPE. 2101 2102 This option enables E0PD for TTBR1 where available. 2103 2104config ARM64_AS_HAS_MTE 2105 # Initial support for MTE went in binutils 2.32.0, checked with 2106 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2107 # as a late addition to the final architecture spec (LDGM/STGM) 2108 # is only supported in the newer 2.32.x and 2.33 binutils 2109 # versions, hence the extra "stgm" instruction check below. 2110 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2111 2112config ARM64_MTE 2113 bool "Memory Tagging Extension support" 2114 default y 2115 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2116 depends on AS_HAS_ARMV8_5 2117 # Required for tag checking in the uaccess routines 2118 select ARCH_HAS_SUBPAGE_FAULTS 2119 select ARCH_USES_HIGH_VMA_FLAGS 2120 select ARCH_USES_PG_ARCH_2 2121 select ARCH_USES_PG_ARCH_3 2122 help 2123 Memory Tagging (part of the ARMv8.5 Extensions) provides 2124 architectural support for run-time, always-on detection of 2125 various classes of memory error to aid with software debugging 2126 to eliminate vulnerabilities arising from memory-unsafe 2127 languages. 2128 2129 This option enables the support for the Memory Tagging 2130 Extension at EL0 (i.e. for userspace). 2131 2132 Selecting this option allows the feature to be detected at 2133 runtime. Any secondary CPU not implementing this feature will 2134 not be allowed a late bring-up. 2135 2136 Userspace binaries that want to use this feature must 2137 explicitly opt in. The mechanism for the userspace is 2138 described in: 2139 2140 Documentation/arch/arm64/memory-tagging-extension.rst. 2141 2142endmenu # "ARMv8.5 architectural features" 2143 2144menu "ARMv8.7 architectural features" 2145 2146config ARM64_EPAN 2147 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2148 default y 2149 help 2150 Enhanced Privileged Access Never (EPAN) allows Privileged 2151 Access Never to be used with Execute-only mappings. 2152 2153 The feature is detected at runtime, and will remain disabled 2154 if the cpu does not implement the feature. 2155endmenu # "ARMv8.7 architectural features" 2156 2157config AS_HAS_MOPS 2158 def_bool $(as-instr,.arch_extension mops) 2159 2160menu "ARMv8.9 architectural features" 2161 2162config ARM64_POE 2163 prompt "Permission Overlay Extension" 2164 def_bool y 2165 select ARCH_USES_HIGH_VMA_FLAGS 2166 select ARCH_HAS_PKEYS 2167 help 2168 The Permission Overlay Extension is used to implement Memory 2169 Protection Keys. Memory Protection Keys provides a mechanism for 2170 enforcing page-based protections, but without requiring modification 2171 of the page tables when an application changes protection domains. 2172 2173 For details, see Documentation/core-api/protection-keys.rst 2174 2175 If unsure, say y. 2176 2177config ARCH_PKEY_BITS 2178 int 2179 default 3 2180 2181config ARM64_HAFT 2182 bool "Support for Hardware managed Access Flag for Table Descriptors" 2183 depends on ARM64_HW_AFDBM 2184 default y 2185 help 2186 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2187 Flag for Table descriptors. When enabled an architectural executed 2188 memory access will update the Access Flag in each Table descriptor 2189 which is accessed during the translation table walk and for which 2190 the Access Flag is 0. The Access Flag of the Table descriptor use 2191 the same bit of PTE_AF. 2192 2193 The feature will only be enabled if all the CPUs in the system 2194 support this feature. If unsure, say Y. 2195 2196endmenu # "ARMv8.9 architectural features" 2197 2198menu "ARMv9.4 architectural features" 2199 2200config ARM64_GCS 2201 bool "Enable support for Guarded Control Stack (GCS)" 2202 default y 2203 select ARCH_HAS_USER_SHADOW_STACK 2204 select ARCH_USES_HIGH_VMA_FLAGS 2205 help 2206 Guarded Control Stack (GCS) provides support for a separate 2207 stack with restricted access which contains only return 2208 addresses. This can be used to harden against some attacks 2209 by comparing return address used by the program with what is 2210 stored in the GCS, and may also be used to efficiently obtain 2211 the call stack for applications such as profiling. 2212 2213 The feature is detected at runtime, and will remain disabled 2214 if the system does not implement the feature. 2215 2216endmenu # "ARMv9.4 architectural features" 2217 2218config ARM64_SVE 2219 bool "ARM Scalable Vector Extension support" 2220 default y 2221 help 2222 The Scalable Vector Extension (SVE) is an extension to the AArch64 2223 execution state which complements and extends the SIMD functionality 2224 of the base architecture to support much larger vectors and to enable 2225 additional vectorisation opportunities. 2226 2227 To enable use of this extension on CPUs that implement it, say Y. 2228 2229 On CPUs that support the SVE2 extensions, this option will enable 2230 those too. 2231 2232 Note that for architectural reasons, firmware _must_ implement SVE 2233 support when running on SVE capable hardware. The required support 2234 is present in: 2235 2236 * version 1.5 and later of the ARM Trusted Firmware 2237 * the AArch64 boot wrapper since commit 5e1261e08abf 2238 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2239 2240 For other firmware implementations, consult the firmware documentation 2241 or vendor. 2242 2243 If you need the kernel to boot on SVE-capable hardware with broken 2244 firmware, you may need to say N here until you get your firmware 2245 fixed. Otherwise, you may experience firmware panics or lockups when 2246 booting the kernel. If unsure and you are not observing these 2247 symptoms, you should assume that it is safe to say Y. 2248 2249config ARM64_SME 2250 bool "ARM Scalable Matrix Extension support" 2251 default y 2252 depends on ARM64_SVE 2253 help 2254 The Scalable Matrix Extension (SME) is an extension to the AArch64 2255 execution state which utilises a substantial subset of the SVE 2256 instruction set, together with the addition of new architectural 2257 register state capable of holding two dimensional matrix tiles to 2258 enable various matrix operations. 2259 2260config ARM64_PSEUDO_NMI 2261 bool "Support for NMI-like interrupts" 2262 select ARM_GIC_V3 2263 help 2264 Adds support for mimicking Non-Maskable Interrupts through the use of 2265 GIC interrupt priority. This support requires version 3 or later of 2266 ARM GIC. 2267 2268 This high priority configuration for interrupts needs to be 2269 explicitly enabled by setting the kernel parameter 2270 "irqchip.gicv3_pseudo_nmi" to 1. 2271 2272 If unsure, say N 2273 2274if ARM64_PSEUDO_NMI 2275config ARM64_DEBUG_PRIORITY_MASKING 2276 bool "Debug interrupt priority masking" 2277 help 2278 This adds runtime checks to functions enabling/disabling 2279 interrupts when using priority masking. The additional checks verify 2280 the validity of ICC_PMR_EL1 when calling concerned functions. 2281 2282 If unsure, say N 2283endif # ARM64_PSEUDO_NMI 2284 2285config RELOCATABLE 2286 bool "Build a relocatable kernel image" if EXPERT 2287 select ARCH_HAS_RELR 2288 default y 2289 help 2290 This builds the kernel as a Position Independent Executable (PIE), 2291 which retains all relocation metadata required to relocate the 2292 kernel binary at runtime to a different virtual address than the 2293 address it was linked at. 2294 Since AArch64 uses the RELA relocation format, this requires a 2295 relocation pass at runtime even if the kernel is loaded at the 2296 same address it was linked at. 2297 2298config RANDOMIZE_BASE 2299 bool "Randomize the address of the kernel image" 2300 select RELOCATABLE 2301 help 2302 Randomizes the virtual address at which the kernel image is 2303 loaded, as a security feature that deters exploit attempts 2304 relying on knowledge of the location of kernel internals. 2305 2306 It is the bootloader's job to provide entropy, by passing a 2307 random u64 value in /chosen/kaslr-seed at kernel entry. 2308 2309 When booting via the UEFI stub, it will invoke the firmware's 2310 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2311 to the kernel proper. In addition, it will randomise the physical 2312 location of the kernel Image as well. 2313 2314 If unsure, say N. 2315 2316config RANDOMIZE_MODULE_REGION_FULL 2317 bool "Randomize the module region over a 2 GB range" 2318 depends on RANDOMIZE_BASE 2319 default y 2320 help 2321 Randomizes the location of the module region inside a 2 GB window 2322 covering the core kernel. This way, it is less likely for modules 2323 to leak information about the location of core kernel data structures 2324 but it does imply that function calls between modules and the core 2325 kernel will need to be resolved via veneers in the module PLT. 2326 2327 When this option is not set, the module region will be randomized over 2328 a limited range that contains the [_stext, _etext] interval of the 2329 core kernel, so branch relocations are almost always in range unless 2330 the region is exhausted. In this particular case of region 2331 exhaustion, modules might be able to fall back to a larger 2GB area. 2332 2333config CC_HAVE_STACKPROTECTOR_SYSREG 2334 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2335 2336config STACKPROTECTOR_PER_TASK 2337 def_bool y 2338 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2339 2340config UNWIND_PATCH_PAC_INTO_SCS 2341 bool "Enable shadow call stack dynamically using code patching" 2342 depends on CC_IS_CLANG 2343 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2344 depends on SHADOW_CALL_STACK 2345 select UNWIND_TABLES 2346 select DYNAMIC_SCS 2347 2348config ARM64_CONTPTE 2349 bool "Contiguous PTE mappings for user memory" if EXPERT 2350 depends on TRANSPARENT_HUGEPAGE 2351 default y 2352 help 2353 When enabled, user mappings are configured using the PTE contiguous 2354 bit, for any mappings that meet the size and alignment requirements. 2355 This reduces TLB pressure and improves performance. 2356 2357endmenu # "Kernel Features" 2358 2359menu "Boot options" 2360 2361config ARM64_ACPI_PARKING_PROTOCOL 2362 bool "Enable support for the ARM64 ACPI parking protocol" 2363 depends on ACPI 2364 help 2365 Enable support for the ARM64 ACPI parking protocol. If disabled 2366 the kernel will not allow booting through the ARM64 ACPI parking 2367 protocol even if the corresponding data is present in the ACPI 2368 MADT table. 2369 2370config CMDLINE 2371 string "Default kernel command string" 2372 default "" 2373 help 2374 Provide a set of default command-line options at build time by 2375 entering them here. As a minimum, you should specify the the 2376 root device (e.g. root=/dev/nfs). 2377 2378choice 2379 prompt "Kernel command line type" 2380 depends on CMDLINE != "" 2381 default CMDLINE_FROM_BOOTLOADER 2382 help 2383 Choose how the kernel will handle the provided default kernel 2384 command line string. 2385 2386config CMDLINE_FROM_BOOTLOADER 2387 bool "Use bootloader kernel arguments if available" 2388 help 2389 Uses the command-line options passed by the boot loader. If 2390 the boot loader doesn't provide any, the default kernel command 2391 string provided in CMDLINE will be used. 2392 2393config CMDLINE_FORCE 2394 bool "Always use the default kernel command string" 2395 help 2396 Always use the default kernel command string, even if the boot 2397 loader passes other arguments to the kernel. 2398 This is useful if you cannot or don't want to change the 2399 command-line options your boot loader passes to the kernel. 2400 2401endchoice 2402 2403config EFI_STUB 2404 bool 2405 2406config EFI 2407 bool "UEFI runtime support" 2408 depends on OF && !CPU_BIG_ENDIAN 2409 depends on KERNEL_MODE_NEON 2410 select ARCH_SUPPORTS_ACPI 2411 select LIBFDT 2412 select UCS2_STRING 2413 select EFI_PARAMS_FROM_FDT 2414 select EFI_RUNTIME_WRAPPERS 2415 select EFI_STUB 2416 select EFI_GENERIC_STUB 2417 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2418 default y 2419 help 2420 This option provides support for runtime services provided 2421 by UEFI firmware (such as non-volatile variables, realtime 2422 clock, and platform reset). A UEFI stub is also provided to 2423 allow the kernel to be booted as an EFI application. This 2424 is only useful on systems that have UEFI firmware. 2425 2426config COMPRESSED_INSTALL 2427 bool "Install compressed image by default" 2428 help 2429 This makes the regular "make install" install the compressed 2430 image we built, not the legacy uncompressed one. 2431 2432 You can check that a compressed image works for you by doing 2433 "make zinstall" first, and verifying that everything is fine 2434 in your environment before making "make install" do this for 2435 you. 2436 2437config DMI 2438 bool "Enable support for SMBIOS (DMI) tables" 2439 depends on EFI 2440 default y 2441 help 2442 This enables SMBIOS/DMI feature for systems. 2443 2444 This option is only useful on systems that have UEFI firmware. 2445 However, even with this option, the resultant kernel should 2446 continue to boot on existing non-UEFI platforms. 2447 2448endmenu # "Boot options" 2449 2450menu "Power management options" 2451 2452source "kernel/power/Kconfig" 2453 2454config ARCH_HIBERNATION_POSSIBLE 2455 def_bool y 2456 depends on CPU_PM 2457 2458config ARCH_HIBERNATION_HEADER 2459 def_bool y 2460 depends on HIBERNATION 2461 2462config ARCH_SUSPEND_POSSIBLE 2463 def_bool y 2464 2465endmenu # "Power management options" 2466 2467menu "CPU Power Management" 2468 2469source "drivers/cpuidle/Kconfig" 2470 2471source "drivers/cpufreq/Kconfig" 2472 2473endmenu # "CPU Power Management" 2474 2475source "drivers/acpi/Kconfig" 2476 2477source "arch/arm64/kvm/Kconfig" 2478 2479source "kernel/livepatch/Kconfig" 2480